Some conventional fingerprint scanners include large, postage-stamp size units, called contact or placement sensors, that sense an entire fingerprint at once (e.g., an entire fingerprint including images of 200-500 rows and 128-200 columns of pixels). Other fingerprint scanners include smaller swipe scanners incorporated into laptop and notebook computers, mobile phones, mobile email devices, and smartphones. Smaller swipe scanners are much less expensive to manufacture than larger placement scanners. Stationary swipe fingerprint scanners sense a finger being swiping across the scanner and can be single line scanners, dual line scanners or multi-line scanners.
One example of a dual line scanner is disclosed in U.S. Pat. No. 6,002,815 issued to Immega et al. on Dec. 14, 1999 (“Immega”), the entire contents of which is herein incorporated by reference. The Immega dual line scanner must determine and track the velocity of the finger as it passes over the sensor and a 1×n pixel array scanner. The Immega dual line scanner performs 1×n linear array cross-correlation on current and historic line scans to initially image the fingerprint. The velocity of the finger must then be known in order to reconstruct the fingerprint image from the line scans.
Conventional fingerprint navigation methods require the velocity of the finger to be known. For example, United States Patent Application Publication No. 2010/0284565, entitled “Method and Apparatus for Fingerprint Motion Tracking Using an In-Line Array,” published on Nov. 11, 2010, and United States Patent Application Publication No. 2008/0063245, entitled “Method and Apparatus for Fingerprint Motion Tracking Using an In-Line Array for Use in Navigation Applications,” published on Mar. 13, 2008, each disclose matrix scanner arrays that image portions of a fingerprint and determine velocity and direction of movement with at least one linear array aligned to a direction of finger movement for user input navigation purposes.
Currently, a user input device (such as a mouse) uses various electrical and optical configurations to track the movement of the user's hand to control the position of a cursor on the screen or to click on icons or links. These can be cumbersome when a portable computing device is being used in a tight space, such as on an airplane, and inconvenient to carry along as an extra item. Built-in user input devices, such as are found on the casings of many lap-top and notebook computing devices, have been found to be difficult to use. Built-in user input devices often lack the feeling of smooth response to the application of pressure to the pressure plate and are often too large and cumbersome for use on mobile phones and handheld computing devices.
Thus, there is a need for a very compact user input device including a fingerprint scanner that can serve to manipulate the position of a cursor on the screen of a computing device.